Stewardship of Tennessee Yellow-eyed Grass, one of the rarest plants in Tennessee

Xyris tennesseensis is a plant that was only discovered in 1978 but by 1991 had been listed as federally endangered.Part of the reason for its listing is its extremely limited distribution, with populations currently known only from one county in Tennessee, four in Alabama, and three in Georgia.

Dr. R. Kral of Vanderbilt University first discovered this perennial monocot obligate wetland plant in Lewis County.Found in calcareous seeps and fens and along streambanks, there are a total of 28 populations in 8 counties. The six populations in Tennessee are restricted to Lewis County, and plants are found in the Highland Rim Seepage Fens, a critically imperiled habitat. In Alabama and Georgia the plants are found in the Southern Ridge and Valley Seepage Fen, also a critical habitat.

Both the Tennessee Dept. of Environment and Conservation (TDEC) and Georgia Dept. of Natural Resources have been receiving funds from the U.S. Fish and Wildlife Service for recovery projects including habitat protection, habitat management, propagation, land acquisition, and research.

There are no state laws in Alabama that protect this species. In Tennessee, one population is in TDEC ownership, five are on private land, two of which are under conservation easements and one of which has a cooperative management agreement with TDEC. Only four sites are protected on federal lands in Alabama with the others on private land. The Georgia sites are all private.

Annual systematic plot monitoring has been done by TDEC’s Division of Natural Areas at four Tennessee populations since 2004. These data show extreme fluctuations in the populations depending on rainfall and woody and herbaceous plant encroachment.

Shading from large trees around the seeps is a threat and will need to be controlled. The seepage fens favored by Yellow-eyed Grass have mesic (moist) soil and gravel substrate that is very fragile. The constant flow of ground water continues in the seeps year-round. Therefore, no heavy machinery can be used for management at any of the X. tennesseensis sites.That’s why since 2004, the Natural Areas Division has conducted manual vegetation management projects at all of the protected sites aimed at controlling both exotic and native plant encroachment.Management activities will need to be continued for many years to come.